SUBJECT ERASING AND PRONOMINALIZATION IN 1TALIAN TEXT GENERATION 
Fiammetta Namer 
LADL 
Universitd Paris VII 
2, place Jussieu 
75251 Paris Cedex 05 
France 
ABSTRACT 
Certain Romance languages such as Italian, Spanish and 
Portuguese allow the subject to be erased in tensed 
clauses. This paper studies subject erasing in the 
framework of a text generation system for Italian. We 
will prove that it is first necessary to try to 
pronominalize the subject. Therefore, we are led to study 
the synthesis of subject and complement personal 
pronouns. In Romance languages, personal pronouns 
raise many syntactic problems, whose solution is 
complex in a generation system. We will see that 
pronominalization plays a fundamental role in the order 
in which the elements of a clause are synthesized, and 
consequently in the synthesis of this clause. Moreover, 
the synthesis of a clause must take into account the fact 
that subject erasing and the synthesis of complements 
are phenomena which depend on each other. The 
complex algorithm that must be used for the synthesis 
of a clause will be illustred in various examples. 
1 Presentation of the generation system 
In a generation system, two questions must be 
answered: "What to say?" (in order to decide on the 
content of the message to be produced) and "How to say 
it?" (producing the text which carries this content). We 
are interested only in the "How to say it?" question. We 
have adapted for Italian the generation system 
developped by L.Danlos (1987a,1987b) which produces 
texts in French and English. This generator includes two 
components: the strategic component and the syntactic 
component. 
1) The strategic component takes both conceptual and 
linguistic decisions. It selects a discourse structure 
which determines the order of information, the number 
and form of the Sentences of the text to be generated. It 
returns a text template which is a list of the form: 
(Sentl Punctl ... Semi Puncti ... Senm Puncm) 
where Puncti is a punctuation mark and Senti a sentence 
template. For the sake of simplification, only sentence 
templates which are clause templates without adverbial 
phrases will be considered here. This means that 
adverbial phrases (e.g. subordinate clauses) and 
coordinations of sentence templates are put aside (L. 
Danlos 1987b). In a clause template (without adverbial 
phrases), which will be noted CI, the elements are in the 
canonical order. 
subject - verb - dir_object - prep_object(s) 
In particular, the subject appears always before the verb 
although the subject can be placed after the verb in 
Italian: 
Ha telefonato Gianni (Gianni has phoned) 
Subject-verb inversion has been described by L. Rizzi 
(1982) as a phenomenon which is correlated with 
subject erasing. This approach may be suitable for an 
analysis system which has to identify the subject of a 
clause. However it is not for a generation system which 
has to synthesize an identified subject. 
This is an example of text template: 
(1) ( CCI1 (:subject MAN1) (:verb amare ) 
Cdir_object MISS1)) . 
CC12 (:subject MAN2) (:verb odiare ) 
Cdir_object MISS2)) .) 
It is made up of two clause templates Cll and C12. 
CI1 includes the tokens MAN1 and MISS1, C12 
the tokens MAN2 and MISS2. These tokens may be 
defined as follows: 
MAN1 =: PERSON MISS1 =: PERSON 
NAME :Max NAME :Lia 
SEX : mase SEX : fern 
MAN2 =: PERSON MISS2 =: PERSON 
NAME : Ugo NAME :Eva 
SEX :masc SEX : fern 
2) The syntactic component synthesizes a text template 
into a text. From the text template (1), it produces the 
following text if the verbs are conjugated in the present 
tense: 
Max area Lia. Ugo odia Eva. (Max loves Lia. Ugo hates Eva) 
Given the following simplified text template, where 
the functional categories (eg. :CI, :subject) are omitted 
for the sake of readibility: 
(2) (MAN1 amare MISS2. MAN2 odiare MISS2) 
(MANI love MISS2. MAN2 hate MISS2) 
the syntactic component synthesizes the first CI as: 
Max area Eva. (Max loves Eva) 
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Then it synthesizes the second one according to the left- 
hand context, i.e. the first synthesized clause. Among 
other things, it computes that the second occurrence of 
MISS2 can be synthesized as a personal pronoun: 
Max area Eva. Ugo la odia. (Max loves Eva.Ugo hates her) 
The different steps required for the synthesis of a 
personal pronoun will be described in section 5.1. In the 
same way, the synthesis of the simplified text template: 
(3) (MAN2 essere cauivo. MAN2 odiare MISS2) 
(MAN2 be nasty. MAN2 hate MISS2) 
gives the following text in which the subject position is 
empty (see section 5.2): 
Ugo d cattivo. Odia Eva. (Ugo is nasty. He hates Eva) 
and the synthesis of the text template: 
(4) (MAN2 picchiare MISS2. MAN2 odiare MISS2) 
(MAN2 beat MISS2. MAN2 hate MISS2) 
gives the following text, in which the subject position 
is empty and the direct object synthesized as a personal 
pronoun: 
Ugo picchia Eva. La odia. (Ugo beats Eva. He hates her) 
2 Synthesis of a dause template 
In a generation system producing texts in Romance 
languages, a syntactic component has to handle three 
different orders for the synthesis of a CI: 
- The order in which the elements appear in a CI (this 
order is supposed here to be the canonical order). 
- The order in which the elements of a C1 must be 
synthesized (see below). 
- The order in which the synthesized elements must be 
placed in the final clause (eg. for Italian, subject-verb 
inversion). This order will not be discussed here. 
The order in which the elements of a CI must be 
synthesized is determined by "non-local dependencies" 
and "cross dependencies" (L.Danlos & F.Namer 1988, 
L.Danlos 1988). A non-local dependency is to be found 
when the synthesis of an element X depends on that of 
another element Y. A cross dependency is to be found 
when the synthesis of X depends on that of Y and when 
the synthesis of Y depends on that of X. For example, 
there is a cross dependency between the synthesis of a 
direct object and that of the verb 1. First, let us show 
that the synthesis of the direct object depends upon that 
of the verb. Consider the following text template: 
(5) (MAN1 e MISS1 essersi sposati ieri. MAN2 adorare 
MISS1.) 
(MAN1 and MISSI get married yesterday. MAN2 adore MISS1.) 
The pronominalisation of the second occurrence of 
MISS 1 is attempted. The foreseen pronoun is la, which 
1 Synthesizing a verb means conjugating it. 
is the feminine singular form of a direct object pronoun. 
This pronoun must be placed directly before the verb and 
must be elided into l' since the verb adorare conjugated 
in the past begins with the vowel a. However, 
synthesizing the second occurrence of MISS1 as l' leads 
to an ambiguous text: 
Max e Lia si sono sposati ieri. Ugo l'adorava. 
since 1' could also be the result of the elision of !o, 
which is the masculine singular form of a preverbal 
direct object pronoun. The interpretation of this text is 
either:. 
or: 
Max and Lia got married yesterday. Ugo adored her. 
Max and Lia got married yesterday. Ugo adored him. 
The second occurrence of MISS1 must therefore be 
synthesized not as a personal pronoun, but as a nominal 
phrase: 
Max e Lia si sono sposati ieri. Ugo adorava Lia. 
(Max and Lia got married yesterday. Ugo adored Lia.) 
This example shows 1) that the synthesis of the direct 
object depends upon that of the verb, 2) that elision, 
which is a morphological operation, could not be 
handled in the final step of the syntactic component of 
the generator. 
On the other hand, the synthesis of the verb depends 
on that of the direct object, since a verb conjugated in 
the perfect tense agrees in number and gender with the 
direct object if the latter is synthesized as a preverbal 
pronoun: 
I ragazzi sono morti. Ugo li ha uccisi 
(The boys are dead. Ugo killed them) 
Le ragazze sono morte. Ugo le ha uccise 
(The girls are dead. Ugo killed them) 
The cross dependency between the verb and the 
direct object can be handled with the following sequence 
of partial syntheses: 
1 - Partial synthesis (conjugation) of the verb, 
without taking into account a possible agreement 
between a past participle and a direct object pronoun. 
2 Synthesis of the direct object, eventually 
according to the first letter of the verb. 
3 - Second partial synthesis of the verb: gender 
agreement with the direct object, if a) the verb is 
conjugated in a compound tense, b) the direct object has 
been synthesized as a personal pronoun. 
The phenomena of non-local and cross dependencies 
make that the synthesis of a CI requires a complex 
algorithm which has nothing to do with a linear 
processus where the elements of a CI are synthesized 
from left to right. We are going to show that the 
synthesis of the subject involves also a number of non- 
local and cross dependencies where pronominalization 
plays a fundamental role. 
- 226- 
3 Introduction to subject erasing 
First of all, it should be noted that subject erasing does 
not affect the other elements of the clause: the verb, for 
example, always agrees with its subject even if erased. 
A subject can be erased only if it can be 
pronominalized since the synthesis of a subject token 
always comes under one of the three following cases: 
1) The token is neither pronominalizable nor erasable. 
2) It is both pronominalizable and erasable. 
3) It is pronominalizable but not erasable. 
In other words, there exists no CI in which the subject 
token is erasable yet not pronominalizable. 
1) In the text template: 
(6) (MISS1 e MISS2 tornare da Londra. MISS2 imparare 
l'inglese.) 
(MISSI and MISS2 be back from London. MISS2 learn English) 
the second occurrence of the token MISS2 can be neither 
pronominalized 2 (a): 
(a) *Lia ed Eva sono tornate da Londra. Lei ha imparato 
l'inglese. 
(*Lia and Eva are back from London. She has learnt English) 
nor erased (b): 
Co) *Lia ed Eva sono tornate da Londra. Ha imparato 
l'inglese. 
(*Lia and Eva are back from London. She has learnt English) 
2) In the text template: 
(7) (MISS2 tornare. MISS2 stare bene.) 
(MISS2 be back. MISS2 be well.) 
the second occurrence of MISS2 can be either 
pronominalized (a) or erased (b): 
(a)Eva ~ tornataJ.~ei sta bene. (Eva is back. She, she is well) 
(b)Eva ~ tornata. Sta bene. (Eva is back. She is well) 
The presence of the pronoun lei in the second clause of 
(a) marks insistence on the entity the pronoun 
represents. 
3) In the text template: 
(8) (MISS2 e MAN2 tornare da Londra. MISS2/mparare 
l'inglese.) 
(MISS2 and MAN2 be back from London. MISS2 learn English.) 
the second occurrence of MISS2 can be pronominalized 
(a) but not erased Co): 
(a) Eva e Ugo sono tornati da Londra. Lei ha imparato 
l'inglese. 
(Eva and Ugo are back from London. She has learnt English) 
2 An asterisk * placed in front of a text means that this 
text is unacceptable because ambiguous. 
(b) *Eva e Ugo sono tornati da Londra. Ha imparato 
l'inglese. 
(Eva and Ugo are back from London. (She+ he) has leamt 
English) 
From the three previous examples, it must be clear that 
there is no C1 in which a subject token is erasable yet 
no pronominalizable. 
Dialogue subject pronouns (i.e. first and second 
person) come under case 2 provided that the verb is not 
conjugated in the subjunctive 3. A verb conjugated in a 
non-subjunctive form indicates always the number and 
person of its subject 4. As a result, a dialogue subject 
pronoun is always erased in non-subjunctive clauses: 
(9) Verrai domani. (You will come tomorrow) 
unless the speaker wishes to insist on the entity the 
pronoun represents: 
(10)Tu verrai domani. (You, you will come tomorrow) 
On the other hand, third person singular subject 
pronouns come under either case 1 or case 2 or case 3. 
For human entities, there are two pronominal forms, 
one masculine lui, and the other feminine lei 5. For non 
human entities, there are also two singular pronominal 
forms: esso (masculine) and essa (feminine). Therefore 
erasing one of these four forms entails the loss of 
information about both the gender of the subject and its 
human nature (i.e. human or non-human). This loss of 
information can give rise to ambiguity. 
Third person plural subject pronouns also come 
under either case 1 or case 2 or case 3. For human 
entities, there is one pronominal form loro used for both 
masculine and feminine. For non human entities, there 
are two forms: essi (masculine) and esse (feminine). 
Erasing a third person plural subject pronoun thus raises 
similar problems than erasing a third person singular 
subject pronoun. Therefore subject erasing will be 
illustrated only with third person singular token 
examples. 
3 Only clauses where the verb is conjugated in the 
indicative will be studied here. 
4L.Rizzi (1982) associates morphological properties (i.e. 
number & person) to the verbal suffix. These properties 
are activated when the subject position is empty. The 
suffix then acts as subject pronoun. 
5 Two other forms can be used: egli (masculine singular) 
and ella (feminine singular). These forms have the same 
behaviour as lui and lei, they are simply used at a more 
literary stilistic level. Therefore only the forms lui and 
lei will be used in this paper. 
A sentential subject can be pronominalized as the 
pronoun ci6. The synthesis of sentential subjects will 
not be discussed here. 
- 227 - 
4 Erasing a third person singular subject which 
can be pronominalized 
The subject pronoun is always erasable in examples 
such as (7) where the left-hand context of the subject 
whose erasing is foreseen contains only one singular 
token. Apart from this trivial ease, let us examine when 
erasing a subject pronoun is possible, i.e. when 
information about the gender of the subject and its 
human nature are both recoverable. 
4.1 Recoverability of the human nature of the erased 
pronoun 
The human nature of an erased subject pronoun is 
recoverable when the verbal predicate lakes only a 
human subject or only a non-human subject. In 
Ugo ha piantato un ciliegio. Esso fruttifica. 
(Ugo planted a cherry-tree. It fructifies.) 
the non-human subject pronoun esso can be erased: 
Ugo ha piantato un ciliegio. Fruttifica. 
(Ugo planted a cherry-tree. It fructifies.) 
since the verb fruttificare can take only a non-human 
subject: 
*(Ugo + lui) frunifica. 
On the other hand, in 
(*0dgo + he) fructifies) 
Ugo ha piantato un ciliegio. Esso ~ ammirevole. 
(Ugo planted a cherry-tree. It is admirable.) 
the pronoun esso cannot be erased: 
*Ugo ha piantato un ciliegio. E" ammirevole. 
(Ugo planted a cherry-tree. (It+he) is admirable.) 
since essere ammirevole takes both human and non- 
human subject: 
(Ugo + lui + questo ciliegio + esso) ~ ammirevole. 
( (Ugo + he + this cherry-tree + it) is admirable) 
4.2 Recoverability of the gender ofthe erased pronoun 
To study when the gender of the subject is recoverable, 
we will suppose that the human nature of the subject is 
recoverable. In the examples below, the verb predicate 
can take only human subjects. 
4.2.1 The gender of the erased pronoun is marked by 
another element of the clause 
If the gender of the subject pronoun whose erasing is 
foreseen is marked by another element of the clause, 
then erasing this pronoun does not give rise to 
ambiguity. Consider the discourses (11) and (12) in 
which erasing the feminine singular pronoun lei (subject 
of the second clause) is attempted: 
(l l )Ugo non vedrh pifi Eva. Lei ~ stata condannata 
all' ergastolo. 
(Ugo will not see Eva anymore. She's been condemned for life) 
(12)Ugo non vedrd pifi Eva. Lei d in prigione per 
omicidio. 
(Ugo will not see Eva anymore. She's in jail for murder) 
Erasing the subject pronoun in (11) does not give rise to 
ambiguity, since the verb marks the gender of the 
subject 6. Ugo, which is masculine, is thus a prohibited 
antecedent. The only possible antecedent of the erased 
subject is Eva and the following discourse where lei is 
erased is unambiguous: 
Ugo non vedr~ pifi Eva. E" stata condannata all'ergastolo. 
(Ugo will not see Eva anymore. She's been condemned for life) 
On the other hand, if the pronoun lei is erased in (12), 
the information about subject gender is lost since 
neither the verb nor any other element of the clause 
indicates it. The antecedents of the erased subject are 
Ugo and Eva. The following discourse where lei is 
erased is ambiguous: 
*Ugo non vedr& pi~ Eva. E" in prigione per omicidio. 
(Ugo will not see Eva anymore. (He + she) is in jail for murder) 
Subject pronoun erasing is therefore prohibited. 
The elements of a clause that mark the subject 
gender are the following: 
- either a nominal or adjectival attribute which is 
inflected for genderT: 
Ugo non vedr~ pifi Eva. E' troppo cattivo (Ugo will 
not see Eva anymore. He is too nasty) 
- or the verb, if it satisfies one of the following 
conditions: 
a) it is conjugated in the passive (see example (11)) 
b) it is conjugated in a compound tense with the 
verb essere (be): 
Ugo non vedrit pid Eva. E' andata in Giappone. 
(Ugo will not see Eva anymore. She's gone to Japan) 
C) it is conjugated in a compound tense at the 
pronominal voice, for example because there is a 
reflexive pronoun: 
Ugo non baller~ con Eva stasera. Si ~ ferito. 
(Ugo will not dance with Eva tonight. He's wounded himself) 
6 The suffix a of its past participle marks the feminine 
singular. Recall that a past participle agrees in gender 
and number with the subject when the verb is conjugated 
with the auxiliary essere (be). 
7 Two classes of adjectives must be distinguished: those 
which are inflected for gender, eg. 
cattivo: mast.sing / cattiva: fern.sing. (nasty) 
and those which are not, eg. 
gentile: masc. sing. & fern. sing. (nice) 
Several classes of nouns must be also distinguished. 
- 228 - 
4.2.2 The gender of the erased pronoun is computable 
from the synthesis of other elements of the clause 
We are going to show that erasing a subject pronoun 
depends on the synthesis of complements of the clause 
(i.e. direct object and prep-objects) because of the 
constraint of no-coreferentiality between a subject and a 
complement personal pronoun. This constraint is based 
on the fact that a complement which is coreferential to 
the subject is synthesized as a reflexive pronoun. 
Therefore, in a clause such as Eva le ha sparato (Eva 
shot her), the indirect complement feminine singular 
personal pronoun le cannot be coreferential to the 
feminine singular subject Eva because if it were it 
would be a reflexive pronoun: Eva si d sparata (Eva shot 
herself). Let us illustrate the use of this constraint for 
erasing a subject pronoun with the following text: 
(13)Eva ~ stata uccisa da Ugo. Lui le ha sparato durante la 
notte. 
(Eva was killed by Ugo. He shot her during the night) 
In (13), there is no subject attribute and the verb is 
conjugated with the auxilary avere (have). Therefore the 
subject gender is only marked in the subject pronoun 
lu/. However if this pronoun is erased, the resulting text 
is not ambiguous: 
Eva ~ stata uccisa da Ugo. Le ha sparato durante la notte. 
(Eva was killed by Ugo. He shot her during the night) 
The only interpretation (the only possible antecedent) of 
the erased subject is Ugo. The indirect complement 
pronoun le can only have a feminine singular 
antecedent, here Eva. The subject and this pronoun 
cannot be coreferent. Therefore the antecedent of the 
erased subject is the only other human which appears in 
the context: Ugo. 
Similarly, consider text (14): 
(14) Ugo non ama pifi Eva. Lui l'ha abbandonata. 
(Ugo does not love Eva anymore. He abandoned her) 
The direct object pronoun l' (elided form of the 
masculine singular lo or of the feminine singular la ) 
does not indicate the gender of its antecedent. However, 
this gender is marked in the feminine past participle 
abbandonata s. The pronoun l' thus refers to Eva. Since 
the antecedent to this pronoun is necessarily different 
from that of the subject, Eva cannot be an antecedent of 
the subject. Erasing the subject pronoun does not give 
rise to ambiguity: 
Ugo non area pifi Eva. L'ha abbandonata. 
(138o does not love Eva anymore. He abandoned her) 
8 Recall that the past participle of a verb conjugated with 
the auxiliary avere agrees in gender and number with its 
direct object if this object is in preverbal position. 
5 Synthesis of a third person singular subject token 
Since a third person singular subject token can be 
synthesized as an empty element only if its 
pronominalization is possible, the synthesis of such a 
token will take place as follows: 
If the token has never been mentioned (see 5.1.b): 
synthesis of a nominal phrase (not described here) 
Else check if pronominalizing it is allowed 
in this case, check if erasing it is allowed 
if it is, synthesis of an empty subject, 
else synthesis of a subject pronoun 
else redescription or repetition of the token (not 
described here). 
We present below: 
1) the different steps to be gone through for the 
synthesis of a subject pronoun, and more generally, for 
the synthesis of a personal pronoun. 
2) the peculiar operations which are necessary in 
Italian for synthesizing a subject pronoun and erasing iL 
5.1 Synthesis of a personal pronoun 
The list of operations required for the synthesis of a 
personal pronoun is as follows: 
a) If a token refers to the speaker(s) or the hearer(s), 
it must be synthesized as a first or second person 
pronoun. The only operation to be performed is then the 
computation of this dialogue pronoun. 
b) Otherwise, we consider synthesizing a token as a 
third person personal pronoun only if it has already been 
synthesized (because it occurs in a previous clause 
template). In other words, we do not consider the left 
pronominalization phenomena 9. Determining whether a 
token which has already been synthesized has to be 
synthesized as a pronoun requires the following steps to 
be gone through: 
1 ° Compute the form of the foreseen pronoun. The 
form of a third person pronoun may depend on its 
syntactical position (subject, direct object .... ), on the 
number and human nature of the token (this semantic 
information is given in the token definition) and on the 
gender of the nominal phrase of the synthesis of the 
previous occurrence of the token. Gender in Italian is 
either masculine or feminine, and it is lexical and not 
9 In fact, the left pronominalization phenomena do rarely 
take place in a system of text generation, except in the 
synthesis of the first sentence, as in: 
Each time he feels bad, U&o is preoccupied. 
where the pronoun he refers to Ugo, right-hand 
antecedent (see among others T.Reinhard (1883)). In the 
n th sentence, the left pronominalization is generally 
forbidden, as shown in the following example: 
Max is feverish. Each time he feels bad, U8o is preoccupied. 
The pronoun he of the second sentence can only refer to 
Max (left-hand antecedent) and not to Ugo (right-hand 
antecedent). As our study is concerned with the synthesis 
of the n th (n > 1) CI of a text template, we put aside left 
pronominalization phenomena. 
- 229 - 
semantic information. Let us consider the following 
definition of the token TABLI: 
TABL1 --: TABLE 
NUMBER: 1 
DEFINITE: yes 
It can be synthesized as a feminine nominal phrase: la 
tavola (the table) or as a masculine nominal phrase: il 
tavolo (the table). The gender of a pronoun is usually 
the same as the gender of the previous occurrence of the 
token: 
(15) La tavola ~ rotta. Ugo la ripara. 
ll tavolo ~ rotto. Ugo Io ripara. 
(The table is broken. Ugo repairs it) 
T Compute the list L1 of tokens that have been 
synthesized in nominal phrases, the morphological 
features (i.e. gender and number) of which are 
compatible with the form of the foreseen pronoun 
provided by Step 1 °. If L1 has only one element, go to 
step 5 ° with L3 = L1; otherwise: 
3 ° Compute the sublist L2 of L1 that contains the 
elements that are semantically compatible with the 
foreseen pronoun. For the pronouns whose form 
indicates the human nature of the antecedent (eg. the 
subject pronoun lui indicates a human antecedent), the 
semantically compatible tokens are those with the right 
human nature. Moreover, the semantic features of each 
non human token of L1 may be checked on with regard 
to the relevant constraints of the verb. For example, in: 
The book is on the table. It was published yesterday. 
the subject of the verb publish used in the passive must 
be something publishable. This semantic information is 
not compatible with the token which represents the 
table, but only with the one which represents the book;, 
the latter is thus the only element which is semantically 
compatible with the pronoun it. If L2 has only one 
element go to step 5* with L2 = L3; otherwise: 
4 ° Compute the sublist L3 of L2 that contains the 
elements which are syntactically compatible with the 
foreseen pronoun. An example of coreferential syntactic 
incompatibility is the constraint of no-coreferentiality 
between a subject and a complement personal pronoun 
(see section 4.2.2). Another one is the following 
constraint: 
If a personal pronoun synthesizes the subject of a 
sentential clause which must be reduced to an infinitive 
form when its subject is equal to the subject of the main 
clause, then this pronoun does not refer to the subject of 
the main clause, because if it did, the sentential clause 
would be reduced to an infinitive form (L.Danlos 
1988):*Mary i wants that Maryileaves --> Maryiwants to 
leave. An illustration of this constraint is that in Mary 
wants that she leaves, the pronoun she cannot refer to 
Mary. 
5* As a first approach, if L3 contains one element, 
synthesizing a pronoun is possible since this synthesis 
involves no ambiguity. Otherwise the foreseen pronoun 
is not synthesized. Counting the number of elements in 
L3 is not enough in determining the possibility of 
synthesizing or not a pronoun: pragmatical 
considerations, focus (C.Sidner 1981, B.Grosz, 1982) 
and parallelism (L.Danlos, 1987a) are phenomena that 
must be taken into account. They are not studied here. 
As an illustration of these five steps, consider the 
following text template: 
(16) (MISS1 e MISS2 tornare. MAN2 dare un bacio a 
MISS2.) 
(MISSI and MISS2 be back. MAN2 give a kiss to MISS2) 
The synthesis of the second occurrence of MISS2 as a 
pronoun is attempted. 
1 ° The form of the preverbal dative pronoun is le, third 
person feminine singular. 
2 ° L1 contains the tokens which appear in the left-hand 
context that have been synthesized as feminine singular 
nominal phrases, i.e. L1 = (MISS I, MISS2). 
3 ° All the elements of L1, which are humans, are 
semantically compatible with the foreseen pronoun, so 
L2=L1. 
4 ° All the elements of L2 are syntactically compatible 
with the foreseen pronoun, so L3--L2. 
5 ° L3 contains more than one element, so the pronoun 
is not synthesized. The resulting discourse will be: 
Lia e Eva sono tornate. Ugo ha dato an bacio a Eva. 
(Lia and Eva are back. Ugo gave a kiss to Eva) 
Another illustration is given by the following text 
template where TABL1 is supposed to be synthesized 
as the masculine nominal phrase il tavolo: 
(17) (MAN1 riparare TABL1. MAN2 dare un bacio a 
MAr~t.) (MANI repair TABLI. MAN2 give a kiss to MAN1.) 
The synthesis of the second occurrence of MAN1 as a 
pronoun is attempted: 
1 ° The form of the preverbal dative pronoun is gli, third 
person masculine singular. 
2 ° L1 contains the tokens of the left-hand context that 
have been synthesized as masculine singular nominal 
phrases, i.e. LI=(MAN1, TABL1, MAN2). 
3 ° TABL1, which is not human, is semantically 
incompatible with the pronoun gli since the dative 
complement of dare un bacio must be human, hence 
L2=(MAN1,MAN2). 
4 ° MAN2, which is the subject of the second CI, is 
syntactically incompatible with gli because of the 
constraint of no-coreferentiality between the subject and 
a complement personal pronoun. Hence L3f(MAN1). 
Since L3 contains only one element, the pronoun can be 
formed: 
Max ha riparato il tavolo. Ugo gli ha dato un bacio. 
(Max repaired the table. Ugo gave him a kiss) 
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5.2 Synthesizing and erasing an Italian subject pronoun 
The synthesis of an Italian subject pronoun follows the 
operations described above, except that erasing the 
pronoun is attempted at the same time, as shown below: 
1) A list L'I is computed parallely to the computation 
of the list L1 (see step 2" of the section 5.1). L'I 
contains the morphological antecedents of the foreseen 
erased pronoun. Two cases must be distinguished (see 
section 4.2.1): 
a There is an element X in the clause which marks 
the subject gender (see example (11)). In this case, L'I 
contains third person singular tokens of the same gender 
as this pronoun. In other words, L'I--L1. 
b There is no element X which marks the gender of 
the pronoun whose erasing is foreseen (see example 
(12)). The morphological antecedents are then the tokens 
of the third person feminine and masculine singular 
(L'I :~ LI). 
If L'I has only one element (this means that LI has also 
only one element) go to step 4) with L'3=L'I; 
otherwise: 
2) A sub-list L'2 of L'I is computed parallely to the 
computation of the list L2 (step 3 ° of the section 5.1). 
L'2 contains the tokens which are semantically 
compatible to the foreseen erased subject. If L'2 (and 
hence L2) contains only one element, go to step 4) with 
L'2=L'3; otherwise: 
3) If the list L3 (step 4 ° of the section 5.1) contains 10 , , 
only one element , the sub-list L 3 of L 2 is computed. 
L'3 contains the tokens which are syntactically 
compatible to the foreseen erased subject. As shown in 
section 4.2.2, computing the list L'3 of the syntactic 
antecedents of the pronoun whose erasing is foreseen in 
a CI depends on the synthesis of other tokens in C1. 
4) Pronoun erasing is usually allowed if list L'3 
contains only one element. 
6 Example of the synthesis of a dause template 
Consider the following text template, where LOC1 is 
to be synthesized as the nominal phrase il bosco (the 
wood): 
(18) (MAN1 vedere MISS1 in LOCI. MAN1 abbracciare 
MISS1) (MAN1 see MISSI in LOCI . MANI kiss MISS1) 
To begin with, suppose the verbs are conjugated in a 
compound tense (i.e. perfect). The synthesis of the first 
CI is then: 
Max ha visto Lia nel bosco. (Max saw Lia in the wood) 
10 If L3 contains more than one element, the subject 
token is not pronominalizable and thus not erasable. 
Let us examine the synthesis of the second CI. First, a 
partial synthesis of the subject MAN1 is carried out. 
Since MAN1 has already been mentioned, both 
synthesizing this token as a pronoun and erasing this 
pronoun are attempted. 
6.1 First partial synthesis of the subject MANI: 
1) The form of the foreseen pronoun is lu/, human 
masculine singular. 
2) The list L1 contains the tokens which appear in 
the left-hand context that have been synthesized as 
masculine singular nominal phrases, i.e. 
LI=(MANI,LOCI). 
The list L'I contains the tokens that have been 
synthesized as both masculine and feminine nominal 
phrases, since there is no element in the CI which 
marks the subject gender; so 
L'I=(MAN1,LOC1 ,MISS 1). 
3) LOCI is semantically incompatible with the 
pronoun lui which can have only human antecedents. So 
L2=(MAN1). 
LOCI is also semantically incompatible with an erased 
pronoun since the subject of the verb abbracciare must 
be human, so L'2=(MAN1,MISS 1). 
4) As L2=L3--(MAN1) contains only one element, 
the synthesis of the pronoun lui is possible. The 
computation of L'3 depends upon the synthesis of other 
elements of the CI. Therefore the final synthesis of the 
subject (i.e. the decision to erase the pronoun lui 
according to the number of elements of L'3) is 
postponed. 
6.2 First partial synthesis of the verb abbracciare 
This verb is conjugated at the third person singular of 
the perfect tense with the auxiliary avere. In this first 
partial synthesis of the verb the possible agreement with 
a direct object is postponed. Thus the result of this 
partial synthesis is the form ha abbracciato where the 
past participle is in the masculine singular form which 
is the default value. 
6.3 Synthesis of the direct object MISS1 
The token MISS1 has been mentioned in the previous 
CI, so'synthesizing it as a personal pronoun is 
attempted: 
1) Because of the conjugation of the verb, the 
feminine singular direct object pronoun la must be 
elided into l'. 
2) The form l' does not mark the gender. However, 
the gender of the pronoun la will be marked in the past 
participle of the verb which is conjugated with the 
auxiliary avere. Therefore, L1 contains the tokens that 
have been synthesized as feminine singular nominal 
phrases, i.e. LI=(MISS1). Since L1 contains only one 
element, the pronoun l' is synthesized. Let us underline 
that the synthesis of the pronoun l" is based only upon 
morphological criteria and thus does not involve the 
constraint of no-coreferntiality between the subject and a 
complement. Therefore this constraint can be used for 
the second (and las0 partial synthesis of the subject as 
shown in 6.5. 
~-Q - 231 - 
6A Second (and last) partial synthesis of the verb 
Since the direct object pronoun 1' has been synthesized, 
the past participle agrees in gender and number with this 
pronoun. The final result of the synthesis of the verb is: 
ha abbracciata where the past participle is in the 
feminine singular form. 
6.5 Second (and last) partial synthesis of the subject 
At this stage, the second CI of (18) is foreseen to be 
synthesized as either Lui l°ha abbracciata or L'ha 
abbracciata. The last step to be carried out is the 
computation of the sub-list L'3 of L'2=(MAN1,MISS 1) 
to determine if the subject pronoun can be erased. Since 
the direct object MISS1 has been synthesized as the 
pronoun l' only thanks to morphological criteria, the 
constraint of no-coreferentiality between a subject and a 
direct object can be used to state that MISS1 is a 
syntactically incompatible antecedent for the foreseen 
erased subject pronoun. So L'3 contains only one 
element: MAN1 and the subject pronoun can be erased. 
The synthesis of the second CI of (18) is: 
L'ha abbracciata. (He kissed her) 
Now, suppose that the verbs of (18) are conjugated 
in a simple tense (eg. present) and examine again the 
synthesis of the second CI. The reader will check that 
the direct object MISS1 can be synthesized as the 
pronoun l' not thanks to morphological criteria (there is 
no past participle) but thanks to the constaint of no- 
coreferentiality. Therefore this constraint cannot be used 
again in computing L'3. Consequently 
L'3=L'2=(MAN1,MISS1) and the subject pronoun 
cannot be erased; the synthesis of this C1 is: 
Lui l'abbraccia. (He kisses her) 
7 Future research 
The sequential order of the operations for the synthesis 
of a C1 we have just described makes that the constraint 
of no-coreferentiality is called on as a priority for the 
synthesis of a complement, and if not used for any 
complement, it is called on for subject erasing. Our 
future research (L. Danlos, F. Namer, forthcoming) 
leads us to design a more global approach in which the 
constraint of no-coreferentiality is not called on as a 
priority for a complement. This approach will allow the 
second CI of (18) (with the verb conjugated in the 
present) to be synthesized not only as Lui l'abbraccia 
but also as 
Abbraccia la ragazza. (He kisses the gid) 
where the subject is erased and the direct object not 
pronominalized because the constraint of no- 
coreferentiality is used for the subject and not for the 
complement. 
ACKNOWLEDGMENTS 
I wish to thank Laurence Danlos for her constant help 
and her important contributions to the work reported 
here. 
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